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MUSC researchers to examine if vitamin D prevents diabetes

By Dawn Brazell | News Center | November 12, 2013

Vitamin DMUSC is investigating if a vitamin D supplement helps prevent or delay Type 2 diabetes in adults who have prediabetes, who are at high risk for Type 2.
Sarah Pack 

MUSC is looking for volunteers to take part in the first definitive, large-scale clinical trial to investigate if a vitamin D supplement helps prevent or delay Type 2 diabetes in adults who have prediabetes, who are at high risk for Type 2.

The multiyear vitamin D and Type 2 Diabetes (D2d) study, funded by the National Institutes of Health, is taking place at about 20 study sites across the United States and will include about 2,500 people. Its goal is to learn if vitamin D – specifically D3 (cholecalciferol) – will prevent or delay type 2 diabetes in adults aged 30 or older with prediabetes. People with prediabetes have blood glucose levels that are higher than normal but not high enough to be called diabetes.

Patrick M. O’Neil, Ph.D., director of MUSC’s Weight Management Center and the study’s principal investigator at MUSC, said this study will definitively assess whether people with prediabetes (who are at greatest risk of developing diabetes) will be less likely to develop diabetes if they receive vitamin D supplementation.

“As with obesity, and in part as a result, the prevalence of diabetes has been increasing greatly in the U.S. In addition to weight loss, other means of preventing diabetes are needed, particularly any which would be inexpensive, easy to use, and accessible.”

O’Neil, professor in the Department of Psychiatry and Behavioral Sciences, said there is a lot of cross-sectional evidence linking Type 2 diabetes, which is the much more prevalent kind that was formerly called "adult onset" diabetes, to low levels of vitamin D in the body.  Some limited evidence also suggests that supplementation of vitamin D may reduce the likelihood of developing diabetes, but those studies have all been incapable of really showing whether it would work.  

D2d is the first study to directly examine if a daily dose of 4,000 International Units (IUs) of vitamin D – greater than a typical adult intake of 600-800 IUs a day, but within limits deemed appropriate for clinical research by the Institute of Medicine – helps keep people with prediabetes from getting type 2 diabetes.  Based on observations from earlier studies, researchers speculate that vitamin D could reduce the diabetes risk by 25 percent.  The study will also examine if sex, age or race affect the potential of vitamin D to reduce diabetes risk.

Patrick O'Neil 

There has been much recent interest in the numerous impacts of inadequate vitamin D levels on health and vitamin D deficiency is quite prevalent especially in certain groups, O’Neil said. Diabetes takes a heavy toll on patients. An estimated 79 million Americans have prediabetes, and nearly 26 million more have diabetes. “There are numerous harmful impacts on the body including cardiovascular disease, kidney disease, vision problems, neuropathy or numbness, high blood pressure and many others.”

Researchers are recruiting volunteers to take part in D2d. Half of the participants will receive vitamin D. The other half will receive a placebo – a pill that has no drug effect. Participants will have check-ups for the study twice a year and will receive regular health care through their own health care providers.

The study will be double-blinded, so neither participants nor the study’s clinical staff will know who is receiving vitamin D and who is receiving placebo. The study will continue until enough people have developed Type 2 diabetes to be able to make a scientifically valid comparison between diabetes development in the two groups, likely about four years.

D2d builds on previous NIH-funded studies of methods to delay or prevent type 2 diabetes, including the Diabetes Prevention Program, which showed that, separately, lifestyle changes to lose a modest amount of weight and the drug metformin are both effective in slowing development of type 2 diabetes in people with prediabetes. However, additional safe and effective preventive strategies are needed to stem the increasing numbers of people developing Type 2 diabetes.
D2d ( number NCT01942694) is supported under NIH grant U01DK098245. The National Institute of Diabetes and Digestive and Kidney Diseases is the primary sponsor of the trial, with additional support from the NIH Office of Dietary Supplements and the American Diabetes Association. The National Diabetes Education Program provides support in the form of educational materials.

Learn more about the study, including how to take part in D2d, at Anyone interested in enrolling locally or in getting more information may call 843-792-5577 and leave a voice mail to request information or may e-mail with "vitamin D study" in the subject line.



Related Stories >>

Vitamin D research leads to first-of-its-kind recommendation for pregnant patients

Related Sources >>

National Diabetes Education Program

NIH Vitamin D Fact Sheet

CDC Diabetes Program

MUSC Weight Management Center

Diabetes Initiative of South Carolina


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